Modern surgery tends toward minimally invasive techniques whenever possible because they reduce pain and accelerate healing. Although often more complicated in some ways for the surgeon, minimally invasive techniques result in less trauma to the patient and less scarring because of much smaller incisions thereby promoting faster healing and reducing possibilities for infections. In general, minimally invasive surgeries involve making one or more small incisions at appropriate locations and inserting tubular devices through the incisions to the surgical site.
The repair, as well as the replacement, of diseased and damaged tissue at a surgical site on or within a patients body is currently preformed using mechanical surgical instruments including simple scalpels which are used for cutting soft tissue, rotable shavers which are also used for removing soft tissue and rotatable burrs which are used for cutting harder tissue such as bone. Elongated surgical cutting instruments are generally known.
In closed surgery such as arthroscopic or more generally, endoscopic surgery, access to the surgical site is gained using one or more portals, and instruments and scopes which are inserted through the incision to the surgical site. Some of these instruments include elongated rotary shavers which have a straight, elongated outer surface and an elongated inner cylincrical member which is concentrically disposed within the outer tubular member. The inner and outer members are sometimes separately and jointly referred to as “blades” or “shavers” and are usually disposable.
In some rotary shavers, each of the shaving members has a proximal and distal end with the proximal end being adapted for rotation by a rotary drive means with a reusable handpiece. The distal end of the inner tubular member may have a cutting means or cutting edge for removal of tissue. In some cases, the distal cutting means cooperates with the opening in the outer member to remove tissue. In some cases rotary burrs are used to selectively affect the tissue. When these elongated instruments are used, they may become clogged with the affected tissue thereby limiting the effectiveness of these instruments during the surgical procedure.
In addition, some of these elongated surgical cutting instruments may utilize a straight or angled shaft. The shaft having the straight configuration may allow for ready removal of the inner cutting instrument from the outer shaft. Allowing for removal of clogged debris or replacement of the inner cutting instrument. However some angled instruments have limitations which prevent removal of the inner cutting instrument form the outer shaft. Utilizing an angled configuration may prevent ready removal and replacement of the inner instrument. It would be desireable to provide a readily removable and replaceable inner instrument during a surgical procedure where the outer member may be cleared of clogging debris or the inner instrument could be replaced with an additional instrument or for use with a nitinol guide wire to maintain the incision during exchange of the inner instrument and outer shaft as desired. In this way, the present invention may help limit the damage caused to the surrounding tissue by unnecessary incisions by requiring new passageways to the surgical site every time the instrument is removed or cleared.
In traditional rotary shaver operation, the inner member rotates in relation to the outer member for cutting the tissue and aspirating it via a vacuum source connected to the proximal end. However, during operation the shaver may become clogged with debrided tissue thereby frustrating the aspirating operation. In a straight shaver instrument often the inner instrument can be removed or a rigid instrument inserted therein for removal of the lodged debris. With a shaving having an angled configuration, running a rigid instrument therethrough is unlikely. Additionally, removal of the inner instrument to remove the lodged debris is also unlikely. Once clogged the shaver apparatus is effectively unusable and a replacement assembly may be required. Because removal of the inner instrument is unlikely, the most common way to dislodge the debris would be to remove the entire shaver apparatus during the procedure, thereby losing the incision and the surgical site becoming inaccessible. Once a new shaver assembly is obtained, then returning to the surgical site may require additional incisions leading to unnecessary and redundant tissue trauma. It therefore would be desirable to have a fixed angle shaver having the ability to remove the inner instrument without loss of the surgical passage. Additionally, it would be beneficial to have a angled shaver adapted for receipt of a rigid instrument within the outer shaft of the shaver member.
During operation of the conventional rotary shaver, the inner blade has a cutting surface which is rotated. Some inner blades are hollow and allow for aspiration, however, the aspiration typically only works when the cutting surface is positioned facing the surgical site. When the cutting surface is rotated within the outer shaft aspiration may not occur or if it occurs, only occurs periodically and not continuously during use. The fluid may surge through the shaver and when the procedure is complete, tissue or other debris may be inadvertently left in the shaver depending on the rotation cycle of the inner blade. It therefore would be beneficial to allow for continuous aspiration of the surgical site through the shaver.